ABSTRACT
Abstract NUMEN proposes cross sections measurements of Heavy-Ion double charge exchange reactions as an innovative tool to access the nuclear matrix elements, entering the expression of the life time of Neutrinoless double beta decay (0νββ). A key aspect of the projectis the use at INFN-Laboratori Nazionali del Sud (LNS) of the Superconducting Cyclotron (CS) for the acceleration of the required high resolution and low emittance heavy-ion beams and of MAGNEX large acceptance magnetic spectrometer for the detection of the ejectiles. The experimental measurements of double charge exchange reactions induced by heavy ions present a number of challenging aspects, since such reactions are characterized by very low cross sections. First experimental results give encouraging indication on the capability to access quantitative information towards the determination of the Nuclear Matrix Elements for 0νββ decay.
Resumen NUMEN propone mediciones de secciones eficaces de reacciones de intercambio de carga doble de iones pesados como una herramienta innovadora para acceder a los elementos de la matriz nuclear, entrando en la expresión del tiempo de vida de la desintegración beta doble sin neutrino (0νββ). Un aspecto clave del proyecto es el uso en INFN-Laboratori Nazionali del Sud (LNS) del ciclotrón superconductor (CS) para la aceleración de los haces de iones pesados de alta resolución y baja emitancia requeridos y del espectrómetro magnético de gran aceptación MAGNEX para la detección de los residuos eyectados. Las mediciones experimentales de reacciones de intercambio de carga doble inducidas por iones pesados presentan una serie de aspectos desafiantes, ya que tales reacciones se caracterizan por secciones eficaces muy bajas. Los primeros resultados experimentales dan una indicación alentadora sobre la capacidad de acceder a información cuantitativa para la determinación de los Elementos de la Matriz Nuclear para la descomposición de 0νββ.
ABSTRACT
Angular distributions of the elastic, inelastic, and breakup cross sections of the halo nucleus ^{11}Be on ^{197}Au were measured at energies below (E_{lab}=31.9 MeV) and around (39.6 MeV) the Coulomb barrier. These three channels were unambiguously separated for the first time for reactions of ^{11}Be on a high-Z target at low energies. The experiment was performed at TRIUMF (Vancouver, Canada). The differential cross sections were compared with three different calculations: semiclassical, inert-core continuum-coupled-channels and continuum-coupled-channels ones with including core deformation. These results show conclusively that the elastic and inelastic differential cross sections can only be accounted for if core-excited admixtures are taken into account. The cross sections for these channels strongly depend on the B(E1) distribution in ^{11}Be, and the reaction mechanism is sensitive to the entanglement of core and halo degrees of freedom in ^{11}Be.
ABSTRACT
Collisions induced by (9,10,11)Be on a 64Zn target at the same c.m. energy were studied. For the first time, strong effects of the 11Be halo structure on elastic-scattering and reaction mechanisms at energies near the Coulomb barrier are evidenced experimentally. The elastic-scattering cross section of the 11Be halo nucleus shows unusual behavior in the Coulomb-nuclear interference peak angular region. The extracted total-reaction cross section for the 11Be collision is more than double the ones measured in the collisions induced by (9,10)Be. It is shown that such a strong enhancement of the total-reaction cross section with 11Be is due to transfer and breakup processes.
ABSTRACT
BACKGROUND: The number of living-related donor kidney transplantations have increased since the advent of minimally invasive surgery. Robotic technology has emerged as a promising alternative to laparoscopic techniques. The authors reviewed their institution experience with robotic hand-assisted donor nephrectomies (RHADNs). METHODS: Between August 2000 and April 2006, 273 robotically assisted left donor nephrectomies were performed using a hand-assisted technique. Prospectively collected information for 214 patients regarding complications, hospital stay, blood loss, warm ischemia time, operative time, and outcomes is presented. RESULTS: The cohort of donors included 110 men and 104 women with a mean age of 36 years (range, 18-61 years). These donors included 86 African Americans, 46 Caucasians, 74 Hispanics, and 8 of other races. Left renal artery anomalies were found in 61 patients (29%). Four patients underwent conversion to open surgery. The hospital stay was 2.3 days (range, 1-8 days), the blood loss 82 ml (range, 10-1,500 ml), and the mean warm ischemia time 98 s (range, 50-200 s). The operative time was 201 min (range, 100-320 min) for the first 74 cases, 129 min (range, 65-240 min) for the second 70 cases, and 103 min for the last 70 cases (p < 0.001), for an overall average of 150 min. Complications decreased significantly after the first 74 cases. The 1-year patient survival rate was 100%, and the 1-year graft survival rate was 98%. The average recipient creatinine at 6 months was 1.4 mg/dl. CONCLUSIONS: Specific changes in operative technique over time have improved patient safety and diminished complications with RHADN. Currently, RHADN can be performed expeditiously with a minimal rate of complications and conversion to open procedure by a surgical team with appropriate training and experience.
Subject(s)
Laparoscopy , Living Donors , Nephrectomy/education , Robotics , Tissue and Organ Harvesting/education , Adolescent , Adult , Female , Humans , Kidney Transplantation , Learning , Male , Middle Aged , Postoperative ComplicationsABSTRACT
OBJECTIVES: we investigated the cause of hypo-responsiveness to vaccines in splenectomized subjects. METHODS: we evaluated the immune responses to a Haemophilus influenzae type b vaccine and the sizes of lymphocyte subpopulations in 25 splenectomized and 45 non-splenectomized thalassaemic patients, in 12 individuals who had been splenectomized after trauma and in 20 controls. RESULTS: the immune response in the controls was significantly higher (P < 0.001) than in splenectomized patients after trauma and in both, the response was higher (P < 0.001) than in thalassaemic patients. In asplenic subjects after trauma, percentages of CD3 and CD4 cells were lower (P < 0.001) than in patients in the other groups; the controls had higher percentages of CD8 cells (P < 0.001) than patients in the other groups. The natural logarithm of the mean percentage of (CD19 showed a quadratic trend from thalassaemic patients through asplenic subjects to controls (P < 0.001). Levels of CD16+ natural killer (NK) cells were higher (P < 0.001) only in asplenic subjects after trauma. CONCLUSIONS: the significant decrease in the immune response of the splenectomized thalassaemic patients vs. non-splenectomized thalassaemic patients may, in part, be due to their basic immunological condition. Thus, the best strategy for protecting these subjects is to vaccinate them before the splenectomy.
